System of motor control.



H. E. STRATTON. SISTEM 0F MOTQR CONTROL. APPLIUATIOH FILED 0015.1, 1908. I 922,540, Patented May 26, 3.909.

2 SHEETB-BHEET 1.

INVENTOR ATTORNEY H. P. STRAT-T-ON.

SYSTEM OF MOTOR CONTROL. APIiLIQATION FILED OUT. 1,1908.

9 22 540; Patented May 25, 1909.

2 SHEETS-BHEET 2.

INVEN'T'QR 2-" m, a a g is 1% vi/1A A'r-roancv rain ci ric.

JHARRY F. STRATTON, OF CLEVELAND, OHIO, ASSIGNOB TO THE ELECTRIC CONTROLLER AND MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

SYSTEM OF MOTOR CONTROL.

T all LU/l 0m it may concern: Be it known that I, HARRY F. STRATTON, a

CltlZGD. of the United States, residing at lowing is a specification.

My invention relates to controllers of the type designated as magnetic switch con trollers', wherein the various circuit changes necessary for the proper control of the motor are accomplished by the opening and closing of magnetically operated switches.

More specifically, my invention relates to a novel and valuable method of insuring that the magnetically operated switches shall always open or close in the right sequence.

The object of my invention is to provide a controller of such design that the closure of any one of the magnetic switches may, because of a temporary large air ga in its magnetic circuit, be impossible unti the closure of a magnetic switch which the proper operation of the controller demands should close previously; that'the closure of any one of the magnetic switches may, because of a temporary large air gap in its magnetic circuit he impossihle until the opening of a magnetic switch which the proper operation of the controller demands should open previously; that the preventive air gap of any one of the mag netic switches may he reduced suliiciently to allow the closure of said switch, by the closure of amagnetic switch which the proper o oration of the controller demands should cose previously; that the preventive air gap of any one of the magnetic switches may be reduced sufficiently to allow the closure of said switch by the opening of a magnetic switcl'i which the proper operation of con troller demands should open previously; that the various auxiliary switches usually carried and operated by the magnetic switches to in sure the proper sequence of closing and opening of said magnetic switches may he eliminated, thereby doing a ay with the troubles arising from the arcing, burning, wearing,

sticking and failure of said auxiliary switches to make contact that the'complicated and extensive system of small control wircs demanded by the use of electrical interlocks reduced to a very simple system oi control wiring, thereby greatly lessening the chances of failure of control. wiring; and in.

Specification of Letters Patent.

Application filed October 1,

Patented May 25, 1909. 1908. Serial No. 455,623.

case of occurrence of such failure, making it much easier to locate trouble.

In the accompanying drawings, Figure 1 shows partly in front elevation and partly in vertical section a set of reversing and accelcrating switches constructed in accordance with my invention, and Fig. 2 shows the circuit connections of a motor system embodying one form of my invention.

Referring to Fig. 1, two posts A carry a slate B supporting eight magnetically operate d switches, U D, U 13?, R, R R and R the switches U D R R and it being shown in vertical section. In the switch U, C is the actuating coil and F is thejplum ger, connected at its lower end to the contact arm G and carrying at its upper end the brass rod 13. H is a laminated stationary brush, with which the contact arm Gr makes contact when the plunger F is in its up er position. P is an iron orsteelplu sleeve on the rod B and free to slide in the tube, on

promptly the source of which the coil C is wound and in which the plunger F slides, and to slide on the rod B. The coil C is inclosed in an iron shell which forms part of the magnetic circuit of-said coil. When the plunger F is in its highest position and the plug P is in its lowest position, the magnetic circuit is practically complete, since the plunger and the plug preferably engage each. other; but at all other )ositions of either the plug P or the plunger 91 there will be an air gap between the phu and the plunger. The strength of the solenoid C is so designed. with relation to the weight of the plunger F and the contact arm G to be ilted, that with the plug P and the plunger F in their lowest positions the pull. of the solenoid on the plunger will be sufficient to raise the plunger and. contact arm when the coil (3 is excited; but with the plug P in its highest position and the plun er F in its lowest position, the air gap wifi he so large that the pull of the solenoid on the plunger will not be suilicicnt to raise the plunger and the contact arm when the coil C is excited.

The same description is, applicable to all of P will be in its lowest position, and

are closed and the switches U 'and U are I connected to the blflSS rod ll" connected to opened, the motor has such circuit connections that a contrarydirection of rotation is obtained. It is, therefore, essential that when the switches U and'U are closed, the switches D and D should be open and vice verse, and also that the switches U and U" should not close until the switches D and l) have opened endv vice, versa.

The first cless levers L and L are mounted respectively upon pins E and and have their ends pivotally connected. The remeining end of the lever L is pivotally connected to rod B and the remaining end of the lever L is pivotally connected to the ears T 2 extending up from the plug P The levers L and L are pivotelly supported on the pins E and E and have the ends between the pins pivotally connected, the remaining end of the lever L being pivotelly connected to the ears T extending up from the plug P end the remaining end of the lever E is piv otally connected to the brass rod B which is carried by the upper end of the plunger vand which is slid-able "within the plug l. The switch arm G is ivotelly connected to the lower end of the p unger F and engages in 'its up er position the brush contact H". By the escribed connection of the plugs, plungers, levers and switch srms, it is seen that when the arm G is closed, and plug P will be in its highest "position, so that it will be impossible by reason of the reventive air gap between the plug and the p unger for the switch arm G to close.- When, however, the switch arm G has fully opened, the phlig tee switch arm G will close when the coil C is excited.

The switches U and D are constructed and interconnected in the some manner as the switches U and D, the reference letters being theseme in both sets of switches, but the exponents of the plugs, the brass rods, the switch arms and brushes are increased by two, and of the levers and pins by four.

- R and R The switches R R R and R are acceler sting switches designed to cut out, step by step, sections of the starting resistance. These switches are constructed the same as the switch U and its arts beer the same reference letters with t 1e exponents increased by four, five, six, and seven for the switches it, lt R, and it, respectively. In the case of the accelerating switches, the proper operation of the controller demands that they should close in the followingorder: R R The connection between the switches R and R is ty icel of the connections between the switcies R and R, and the switches it and R The first class lever L carried by the pivot pin E is pivotelly connected its ends to the rod B and the plug P. The "first class lever L pivoted on the pin E has one end i end of the section 18 of the resistance.

opposite ends connected to the rod E of the switch R and the plug P of the switch it. The plug P oi" the switch R is stationery.

The switch R is shown closed, which closes themsgnetic ci zit through. the plug P and the plunger The lever l! moved the plug 1 to its lr JQSt position that the air gephetwec he plug and the plunger has become so re mod that, when the coil (3 is ener ized, the su tch it will close. So long as the switch l is open, the lever D will keep the plug P at its high 5 position, making sir gap in the coil it too long to permit the switcl'l 1t to close even if the coil (1 be energized. Siinlls the switch ll cennot close so long a 'L i K i .L! switch it is open. li hen the switch open, the air gaps in the switches It, i R are too great to permit them to close, but the plug P is ehvuys in position to render the magnetic flux between it and the plui'igcr Ff effective to lift the plunger P when the coil C is energized. Thus when the switches it to R are all open, the switch ll is necessarily the first one to close. The remaining switches RHR and R must close in the definite order described.

Referring now to Fig/2, which is wholly diegrei'ninetic, I show the master controller K having the contact lingers 20 to 26 cofiperetive on one side with the contacts 27 to 32 connected by the conductor 33, and on the other side with the contacts to 39, connected by the conductor he linger 20 is connected by the wire H) to positive pole of the switch S; the linger 2i, by the wire 46 to the upper ends of the coils C and C. the linger 22, by the wire 45, to the upper ends of the coils and C the lingers 23 to 26, by the wires 44, 43, 42, and 4-1 to the upper ends of the coils (.7? to C, respectively. The switch arms/G and G are connected to the wire 8 leading to one end of the field coil F of the motor; the switch arm G is connected to the brush H and to the wire 10 leading to one end of the ermetureAof the motor; the switch arm Gr is connected to the brush H and to the wire 12 leading to the remaining 'end of the armature A. The switch er'lns G" to G are connected by the wire 2 to the wire 1 leading to the negative pole of the switch S, and also connected to the remaining ends of the coils C to C respectively. The brushes H and H are connected by the wire-14 to the positive side of the switch S; and the brushes H tojH are connected to the resistance B so as to'divide it into the three sections 16, 17, and 18 by means of the wire 3, 4, 5 and 6 The remain ing end of the field F is connected to the 0%61' h as wire 48 connects the negative Wire 1 with the I ing contact with which said movable contact I lower end of .the 0011 C and through the wire may make electricalconnection, a magnetic 47, with the lower ends of the coils C C circuit forthe actuating coil, said magnetic and C The operation is as follows: The master controller K being moved to position a, the

' current will flow from the positive side of the switch S through the wire 19, the finger 20, the contacts 34 and 35, the wire 46, the coils C and C the wires 47 and 48, and the wire 1 to the negative side of the switch S. This circuit closes the switches D and D At the same time a branch-circuit extends from the contact-35 through the contact 36, the finger 23, the wire 41 and the coil (1 to the wire 1, this branch circuit closing the switch The motor circuit is now established as follows: From the positive pole of the switch S through the wire 14, the wire 15, the brush H, theswitch arm G, the wire 13, the wire 12, the armature A, the wire 10, the brush H the switch arm G the wires 9 and 8, the,

field coil F, the wire 7, the entire resistance R, the brush H the'switch arm G and the combination of an actuating coil,

and C to the wires 47 and 48 w wire 1, to. the negative pole of the switch '8.

-As the controller is moved to the positions I), c and d, the fingers 24, 25 and 26 engage the contacts 37, 38 and 39 which energize the coils C, C, and C in succession, causing the switches R R and R to in the manner andfor the reasons already 'explained. When the controller is moved to the positions a to dthe circuits are the same as at the positions a to d except that the wire 46'and the coils C and C are dead and the wire 45 carries thecurrent from. the finger 20 and contact 27 throu h the coils C ich change in the circuits causes the motor circuit to pass from the wire 14 through the switch U the Wire 10,the armature A, the wire 12, and the switch U to the wire 8, from which the current flows as previously described. As the current'through the armature A' is contrary to its former direction while that through the field F is the same, the direction of rotation of the armature is reversed.

The principles of the o eration of the several magnetic switches as been fully explained and need not be repeated in considermg Fig. 2. a

I claim 1. In a magnetically operated switch, the a plun er operated by said actuating coil, a movable contact operated by said plunger, a cooperatr circuit having an air gap sufficiently large to successively close,

prevent the operation of the lunger'upon excitation of the actuating coi and means for reducing the preventive air gap sufficiently to allow the operation'of the plunger upon excitation of the actuating coil.

2. In a magnetic switch controller, magnetically operated switches, some of the said switches having air gaps in their magnetic circuits sufficiently large to prevent the operation of the respective switches upon excitation of their actuating coils, and means whereby said preventive air gaps maybe reduced sufficiently to allow the operation of said switches upon the excitation of their acf' iatmg coils by the closure of that switch, which the re er operation of the controller demands s on (1 close previously.

3. In a magnetic switch controller, magnetically operated switches, said switches having air gaps in their magnetic circuit sufficiently large to prevent the operation of the respective switches 1])0I1 excitation of their actuating coils, and means whereby said reventive air I gaps may be reduced sufiiciently to allow the .operation ofsaid switches upon the excitation of their actuating coils by the opening of that switch, which the ro er 0 eration of the contr0llerde man s s oul open previously.

4. In an electric controller, a series of electro-magnetically operated switches, certain of said switches having air gaps in the mag-- netic circuits of their actuating electro-magnets, and means o erated by the actuation of one switch for iminishing the air gap in the magnetic circuit of another switch, such that said first switch must always be actuated before said second switch'can operate. 5. In an electric controller, two or more electro-magnetically operated switches, an adjustable air gap in the magnetic circuit of the actuating electro-magnet of one of said switches, the extent of said air. gap being adjusted between limits by the operation '0 another of said switches;

Signed at Cleveland, Ohio, of September, A. D. 1908.

HARRY. )STRATTON.

this 21st day Witnesses i v H. M. DIEMER, F. W. Jnssor. 

